Time of Concentration
Time of Concentration
(OP)
I'm working on a project that has an existing pond on the property. I delineated the drainage basin contributing stormwater runoff to the existing pond. My question is: How should I determine the flow path for time of concentration calculations. I'm using the LAG method. I have two options both begin at the most hydraulic point in the basin. Option-1 is to end the flow path when runoff first enters the pond. Option-2 is to end the flow path at the pond outlet. The difference in flow path distance is 450 feet. I'm not sure what option best describes the time of concentration.





RE: Time of Concentration
RE: Time of Concentration
Note: If you are not doing a separate pond routing calculation, it's possible to include the pond as part of the Tc, perhaps using the wave velocity. However, it's more accurate to use a separate hydrograph routing to simulate the pond's behavior.
Peter Smart
HydroCAD Software
www.hydrocad.net
RE: Time of Concentration
I agree with terry
RE: Time of Concentration
At least that's what I recall. . .
f-d
¡papá gordo ain’t no madre flaca!